Process of sterilizing food



ntmted Apr. 29, 193% OSWALD E. HANSEN, OF CEDARBUBG, WISCONSIN, ASSIGNO MACHINERY CORPORATION, OF CEDARBURG, WISCONSIN, A CORPORAT CONBIN I PROCESS OF STERILIZING F OOD rte Drawing. Application filed June 15, 1929. Serial No. 371,304,

The present invention relates in general to improvements in the art of heat treating edible substances having certain characteristics, in order to sterilize and to permanently pre- 6 serve the same by destroying bacteria and other harmful micro-organisms therein.

An object of the invention is to provide an improved process of rapidly and effectively sterilizing certain kinds of food products, and

l of permanently maintaining the treated substances in sterile condition.

As a result of the more recent introduction of high speed canning machinery with its resultant enormous capacity, the matter of 2& efiectively sterilizing the vast output of the modern filling and closing mechanisms, becomes an important problem requiring careful consideration. In order to avoid limitation of the capacity of the canning factory as F 4 a unit, the sterilizing and other processing operations must keep pace with therapid tune-- tioning of the measuring, filling and closing machinery. The degree of sterilization of the product, must however be sufficient to in- 2 sure complete destruction of all of the bacteria, and thd treated material must be finally packed in the containers under sterile conditions in order to maintain the commodity free from subsequent spoilage.

Certain classes of food products such as strawberries, raspberries, and the like will not readily withstand being subjected to their sterilizing temperature or any great length of time, without seriously degrading the quality thereof. Many of these products moreover have normall sterile cores, all of the destructive bacteria eing confined to the outer portions of the granules, thereby making complete penetration of the granules or berries,

with sterilizing heat, unnecessary.

In order to avoid degradation of such products, they should be sterilized as quickly as possible, and the sterilized granules should preferably be maintained submerged in a sterile liquid in order to permanently pre irsassa OFFICE n ro HANSEN CANNING- Ion or wrs nrran' sraras ears serve the same. If the submerging liquid is hile cold and the entire mass of mixture is subsequently h ilizing temperature, the too slow, and too long effect the treatment.

to penetrate a rela mixture, may otherwise damage source of heat. Due to the relativel ture of the cells of such commo ities, ranules or berries must not be violently heated because such treatment will also result in deterioration of the product.

invention con eated up to the'sterheat penetration is a time is re The heating required ly thick mass of the be sufficient to'burn or the granules nearest to thetemplates prod method of rapidly and commodities possessing without in any g the product, by utilizing he purpose of simultaneousthe granules and protecting nst spoilage.

In accordance w1 ment, the pres and allowed to cool to an The sterile liquid ciently heated condition and efiective sterilizat the particular co The present vision of an improve effectively sterilizing the foregoing ch manner degradin heated liquid f ly sterilizing aracteristics,

th the present improveerving liquid is first sterilized y desired temperawhile still in Sufito insure complete of the granules of dity being treated, is to fill the voids of the gran- The heat confined in the liqquickly and thoroughly f the individual t desterilization. As the liquid is absorbed by the temperature of the quickly, therethe berries due ular material. uid thus applied, sterilizes each 0 prevents subsequen heat of the preserving the granules or berries, mixture naturally drops ver by avoiding deterioration o to lengthy overhe In practicing ranular materia ulk or in segregated material may if a temperature somew heat thereof, in order 'anules and the improved 1 may be treated either in batches. The granular d, be initially heated to hat below the degrading to hasten the subsequent W process, the,

. to a source of relatively high heat. After the globular structure,

sterilization and to avoid excessive temperature differences. This initial heating may be effected when treatin the product in bulk, while the granules w ich are ordinarily of are being rolled gently over a heated surface or plate, in the form of a thin layer, or the'heat may be applied to measured batches of the granules after having been placed in the final containers or cans but before closing thereof.

The preserving liquid may be rapidly and thoroughly sterilized by subjecting a constantly'advancing film or thin layer thereof,

temperature of the sterilized liquid has been sufllciently reduced to avoid injuring the granules when directly applied, enough of, the hotliquid is mixed with the granular material to completely fill all voids and to submerge all of the granules. If the product is being treated in bulk, a constantly advancing stream of mixture may readily be produced y regulating the rate of progression of the berries and the quantity of liquid admitted to the path of travel of the berries. If batch treatment is resorted to, accurately remeasured batches of-th'e preserving liqui may be deposited in the successive containers or cans having therein premeasured batches of the granules. As previously stated, the hot liquid upon commg in contact with the cooler granules, quickly transmits heat thereto and effectively destroys the bacteria therein. This transfer of heat results in a rapid reduction in the temperature of the mixture, below the sterilizin temperature of the granular material. T e finally sterilized mixture should then be hermetically sealed in the containers or cans in a sterile atmosphere such as a. steam pendent upon t bath, in order to insure tion of the commodity.

If the material being treated is of the class having a normally sterile core, the liquid may permanent preservabe applied at a lower temperature than when ective heat treatment of such products at a sufliciently rapid rate of speed to keep pace with the igh speed fillers and closing machines, and insures thorou h sterilization of all portions of each individual batch of material treated.

Although the present improved method is unquestionably applicable with marked ad- 'ters Patent vantage to the treatment of various kinds of fruits and other vegetation, it is believed that certain other classes of hardier commodities may be more advantageously treated by another process forming the subject of a copending application S.'N. 371,303, filed June 15,1929.

It should be understood that it is not intended to limit the'present invention to the exact steps of the method specifically described herein by way bf illustration, for various modifications, within the scope of theappended claims may occur to persons skilled in the art.

It. is .claimed and desiredto secure by Letsterilizing, which comprises, admitting to the voids of pre-heated solids a liquid of temperature suficicntly high to completely sterilize the mixture.

2. The process ofsterilizing, which comprises, filling the voids of granular pre-heated solids withv a sterile liquid of temperature only sulficient to insure complete sterilization of the mixture.

3. The process of sterilizing, which com prises, admitting toythe voids of successive measured batches of preheated solids alone, batches of liquid of temperature suficiently high to completely sterilize each batch of mixture.

4. The process ofsterilizing, which comprises, filling the voids of successive measured batches of granular pre-heated solids with sterile batches of liquid of temperatureonly sufiicient to insure complete sterilization of each batch of mixture.

5. The process of sterilizing, which comprises, heating granular solids alone to a teml. The process of erature below the sterilizin tem erature p a; P

thereof, and subsequently completely sterilizing said solids by admitting to the voids thereof sterile liquid having a temperature sufiiciently high to effect such complete sterilizae tion.

6. The process of sterilizing, which comprises, heating batches of granular solids alone in succession to temperatures below the sterilizing temperature of the sequently admitting to the voids of each batch suificient liquid of temperature suficiently high to eli'ect complete sterilization of the batches of mixture.

7. The process of sterilizin%, which com- 1 prises, filling the voids of granu ar pre-heated solids with a sterile liquidof temperature sufiiciently high to insure complete sterilization of the mixture, and subsequently hermetically sealing the sterilized mixture under sterile conditions.

8. The process of sterilizing, which comprises, admitting to the voids of successive measured batches of pie-heated solids batches of liquid at tem eraturesuificiently high to completely steri e each batch of stars,

solids, and suband subsequently packing the sterile batches in containers under sterile conditions.

9. The process of sterilizing, which oomthereof, subsequently completely sterilizing said solids by admitting to the voids thereo sterile liquid having a temperature sufiicientl high to effect complete sterilization, and fina ly hermetically sealing the sterilized mixture under sterile conditions.

In testimony whereof, the signature of the inventor is affixed hereto.

OSWALD H. HANSEN. 

